Spark-plug attachment.



N. R. MICHAEL.

smx me ATTACHMENT. APPLICATION FILED APILZB. I911.

1,241,751. Patented 0% 2,1917.

NORMfiN R- MTcHHEL NORMAN B. llIICI'IAEL, OF MAINVILLE, PENNSYLVANIA.

SPARK-PLUG ATTACHMENT.

Specification of Letters Patent.

Patented on. 2, 1917.

Application filed April 28, 1917. Serial No. 185,236.

To all whom it may concern:

Be it known that I, NORMAN R. MICHAEL, a citizen of the United States, residing at Mainville, in the county of Columbia and biute of Pennsylvania, have invented. certain new and useful. Improvements in Spark-Plug Attachments, of which the following is a specification, reference being bad to the accompanying drawings.

This invention relates to spark plugs and its general object is to provide a spark plug by which the driver of the engine may read- 11y see whether the plug is sparking properly or not.

A further object of the invention is to provide a plug with an inclosed spark gap. the wall, surroumiliiw the gap being of trans parent material, aim means being provided whereby the spark cap may be increased or decreased until. the iest effect is secured, this adjustment of the spark gap within the transparent housing indicating the proper adjustment of the electrodes in the spark plug.

A further object of this invention is to provide an attachment of this character which may be readily connected to spark plugs now in use and which will not necessilatr any change in the ordinary construction of the spark plugs.

A further object of my invention is to provide means whereby it may be seen whether or not a spark pin is sparking properly without increasing t 1e size of. the ordinary plug.

And a further object is to provide a device of this character which may be used on any plug and to provide means whereby the electrodes of the plug may be properly adjusted in accordance with the adjustment of the spark gap in the attachment.

Other objects will appear in the course of the followin description.

My invention is illustrated in the accom-- pa'nying drawings, wherein Figure 1 is an elevation of a spark plug firovided with my attachment, the cylinder being shown in section;

Fig. 2 is a sectional view of the attachment itself on an enlarged scale.

Referring to the drawings, 10 designates the usual base of the spark plug which, as usual, is screw-threaded at 11 for engagement with the wall of the cylinder or firing chamber, the base above this screw-threaded portion being many-sided to permit the application of a wrench thereto. Having screw-threaded engagement with the base is the usual metallic bushing 12, screw-threaded as usual for engagement with the base and disposed within the base is a core 14 of porcelain or other insulating material through which core the electrode 15 passes. This electrode extends downward to a point in, line with the lower end of the base and the base is provided with the conn ting electrode 16, all of these parts being (if any ordinary or usual construction.

lhe upper end of the electrode is screwthreaded as at 17 and the electrode 15 is held in its adjusted position by means of the usual jam nut 18, the electrode 15 extending above this jam nut. My attachment comprises a cylindrical housing which may be made of glass or translucent material and which is designated 19. This housing is closed at its lower end by a cap 20 and at its outer end by a ca 21, these caps being metallic and prefers. )ly the side wall of each cap is forced into a groove 21 formed in the glass cylinder 19, thus holding the cap securely in place without the necessity of using any cement, which is very liable to become dry and which, by the constant vibration to which the plug is submitted, will have a tendency to become disengaged from the housing 19. The cap 20 is formed with a thickened central riorly screw-threader for engagement with the screw-threads 17. The cap 21 has also a central thickened portion which is interiorly screw-threaded for engagement with an electrode section 23. The electrode 23 is exteriorly screw-threaded and may be adjusted through the cap 21 toward and from the extremity of the electrode 15. The electrode 23 extends above the cap 21 and mounted upon the electrode is the jam nut 24 and the binding nut 25.

In the actual operation of this invention, the electrode 23 is electrically connected in the ignition system as usual, :1 pro or spark gap being left between the electro c section 23 and the electrode section 15. Now when the high tension current passes through the electrode section 23 and the electrode 15, a spark will be formed between the section 23 and the end of the electrode 15 and between the electrode 15 and the electrode 16. Inasmuch as the wall 19 is transparent, an obortion which is intoserver may readily see whether the spark plug of any particular cylinder is operatmg properly or not and can correct the adjustment of the electrodes or remove the spark plug and replace it, if for instance the insulation is defective or carbon has deposited to such an extent as to prevent the proper operation of the electrode. Furthermore, by adjusting the electrode section 23 toward or from the extremity of the electrode 15, the observer may see just what gap gives the best and hottest spark and may thus adjust the electrode with relation to the electrode 16 so as to secure the best possible spark. It Will be seen that this construction is very simple, may be readily applied to spark plugs now in use or the ordinary spark plug may be reduced in length in order to permit the application of the attachment thereto. It will be also seen that by attaching the caps to the glass 0 linder 19 in the manner described, there wi 1 he no danger of the caps becoming detached from the glass A spark plug attachment comprising a cylindrical transparent housing formed with annular grooves adjacent its opposite ends, metallic caps embracing the ends of the housing and having bea s engaging in said grooves, each of said caps having a screwthreaded central aperture, one of said apertures being adapted to receive the electrode of a spark plug, an electrode section passing through the screw-threaded aperture of the other cap and adjustable therethrough, and binding nuts on the electrode section.

In testimony whereof I hereunto afiix my signature in the presence of two Witnesses.

NORMAN R. MICHAEL.

WVitnesms V Maumon E. Krcnonr, R. F. MICHAEL. 

